THE PHARMACOLOGICAL ACTION OF TUTU. 



309 



The chief seats of origin of tutin convulsions in rabbits and cats would therefore 

 appear to be the cortical centres and the pontine nuclei. The share which each of these 

 centres takes in producing the convulsions in unanaesthetised and unmutilated animals 

 is difficult to prove ; but from the nature of the anxiety of the preconvulsive stage 



4.27 



Fig. 9. — Effect of tutin on fore limbs after excision of left cerebral hemisphere. Cat, 

 1750 grm. Ether. 3.30, left cerebral hemisphere removed. 4.0, 1 mg. tutin intra- 

 venously. 4.16, 0'5 mg. tutin intravenously. The small contractions of right fore 

 limb (R) were transmitted from left shoulder muscles. Time in seconds, x f linear. 



aud the character of the early convulsions I am inclined to believe that the earliest 

 action is upon the cortical centres. The continued clonus of the late stages, which is 

 associated with complete unconsciousness, is in all probability due to the activity of the 

 lower centres. 



Action on the Higher Centres. 



Owing to the ease with which reflex phenomena are obtained after the administra- 

 tion of tutin, it is impossible to say definitely, from the observation of rabbits, that 

 tutin in small convulsant doses has an action on the sensory and other higher centres. 

 Decided depression and even sleepiness are seen in these animals soon after the injection 

 of such doses ; but, although I am of opinion that this condition is the result, in part if 

 not wholly, of an action on the higher centres, I was unable to convince myself that it 

 is not secondary to the changes in the respiratory and circulatory systems, or due to a 

 desire to keep the muscles at rest as long as possible. It is noteworthy, however, that 

 the same degree of depression was not noted after coriamyrtin, which acts more rapidly 

 but otherwise produces the same kind of convulsions as tutin ; and it is not seen after 

 strychnine when given in sufficient doses to cause convulsions. After the administra- 



